Unveiling White Light Emission of a One-Dimensional Cu(I)-Based Organometallic Halide toward Single-Phase Light-Emitting Diode Applications.

Luminescent organometallic halide crystals, especially with single-component white emission, are urgently needed for light-emitting diode (LED) applications. Barriers for the applications, however, lie in their lead toxicity, poor stability, and low photoluminescence quantum yield (PLQY). Here, a one-dimensional Cu(I)-based hybrid metal halide (C 12 H 24 O 6 )CsCu 2 Br 3 is designed and prepared via a simple solution method. Upon 365 nm excitation, a broad-band white light emission centered at 535 nm with a full width at half maximum of 186 nm and a PLQY of 78.3% is monitored. The experimental results together with calculation data indicate that the existence of the split peaks at 486 and 570 nm at a low temperature is attributed to the decrease of energy level degeneracy by virtue of the lattice distortion. Moreover, the stability along with the good device performance of the as-fabricated white LED was also discussed. The results demonstrate that (C 12 H 24 O 6 )CsCu 2 Br 3 is highly competitive in lighting application, and it can further enable breakthrough material design for new luminescent organometallic halides.